Document Type : Review Article


1 Ph.D. Students of Animal Physiology, Faculty of Agriculture, University of Tabriz, Tabriz, Iran

2 Professors, Department of Animal Science, Faculty of Agriculture, University of Tabriz, Tabriz, Iran

3 Assistant professor, Department of Anatomical Sciences, Faculty of Medicine, University of Medical Sciences, Kermanshah, Iran


The bio-stimulation technique offers a potentially useful and practical way for reproductive performance in rams. Reports on how bio-stimulation affects sexual potency rams are scarce: Knowledge of how rams respond to bio-stimulation is useful for persons who involved in semen collection; "hand" (controlled) mating, and the administration of sexual performance evaluations. The reduction of the stimulus value of the ewes after several, or even after one mating, appears to be the major factor accounting for the temporary interruption of the sexual activity of the rams. Sexual stimulation provided a definite, clearly recognizable end point for establishing that a ram was sexually stimulated


Banks EM (1964). Some aspects of sexual behavior in domestic sheep, Ovis Aries. Behavior 23, 249–279.
Brennan PA, Kendrick KM (2006). Mammalian social odours: attraction and individual recognition.Philos. Trans. R Soc Lon B. Biol. Sci. 361, 2061-78.
Chanvallon A, Fabre-Nys C (2009). In sexually naive anestrous ewes, male odour is unable to induce acomplete activation of olfactory systems. Behav. Brain. Res. 205, 272-279.
Chenoweth PJ (1981). Libido and mating behavior in bulls and rams. Theriogenology. 16 (2), 155-177.
Cohen-Tannoudji J, Einhorn J, Signoret JP (1994). Ram sexual pheromone: first approach of chemical identification. Physiology and Behavior 56, 955–961.
Fahey AG, Duffy P, Fair S (2012). Effect of exposing rams to a female stimulus before semen collection on ram libido and semen quality. J. Anim. Sci. 90, 3451-3456.
Gabriela SA, Keith MK (2009). The main olfactory and social learning in mammals. Behav. Brian. Res. 323-335.
Gonzalez R, Orgeur P, Poindron P, Signoret P (1991). Female effect in sheep. I. The effects of sexual receptivity of female and the sexual experience of rams. Repord. Nutr. Dev. 31, 97-102.
Hawken PAR, Beard AP (2009). Ram novelty and the duration of ram exposure affects the distribution of mating in ewes exposed to rams during the transition into the breeding season. Anim. Repord. Sci. 111, 249-260.
Hawken PAR, Esmaili T, Scanlan V, Blache D, Martin GB (2009). Can audio–visual or visual stimuli from a prospective mate stimulate a reproductive neuroendocrine response in sheep? Animal. 3 (5), 690-696.
Knight TW, Lynch PR (1980). Source of ram pheromones that stimulate ovulation in the ewe. Anim. Reprod. Sci. 3, 133–136.
Levy F, Locatelli A, Piketty V, Tillet Y, Poindron P (1995). Involvement of the main but not the accessory olfactory system in maternal-behavior of primiparous and multiparous ewes. Physiol. Behav. 57, 97-104.
Maina D, Katz LS (1999). Scent of a ewe: Transmission of a social cue by conspecifics affects sexual performance in male sheep. Biol. Reprod. 60, 1373-1377.
Martin GB, Milton JTB, Davidson RH, Banchero Hunzicker GE, Lindsay DR, Blache D (2004). Natural methods for increasing reproductive efficiency in small ruminants. Anim. Repord. Sci. 82-83, 231-245.
Moghaddam GH, Olfati A (2012). Effects of change of the stimulus ewe on sexual performance of crossbred rams. Proceedings of the 15th AAAP Animal Science Congress, Thammasat University, Rangsit Campus, Thailand.
Olfati A, Moghaddam GH, Alijani S, Rafat SA (2012). Effects of visual stimuli or change of the stimulus ewes on libido and semen characteristics of crossbred rams during breeding season. Slovak. J. Anim. Sci. 45 (3), 76-82.
Petrulis A, Alvarez P, Eichenbaum H (2005). Neural correlates of social odor recognition and the representation of individual distinctive social odors within entorhinal cortex and ventral subiculum. Neuroscience. 130, 259-74.
Rekwot PI, Ogwu D, Oyedipe EO, Sekoni VO (2000). The role of pheromones and Biostimulation in animal reproduction. Anim. Repord. Sci. 65, 157-170.
Rosa HJ, Juniper DT, Bryant MJ (2000). Effects of recent sexual experience and melatonin treatment of rams on plasma testosterone concentration, sexual behavior and ability to induce ovulation in seasonally anoestrus. J. Reprod. Fert. 120, 169-176.
Suta D, Popelaˇr J, Syka J (2008). Coding of communication calls in the subcortical and cortical structures of the auditory system. Physiol. Res. 57(Suppl3):S149–59.
Tate AJ, Fischer H, Leigh AE, Kendrick KM (2006). Behavioural and neurophysiological evidence for face identity and face emotion processing in animals. Philosophical Transactions of the Royal Society of London B-Biological Science. 361, 2155-217.
Vignozzi L, Filippi S, Morelli A, Luconi M, Jannini E, Forti G, Maggi M (2008). Regulation of epididymal contractility during semen emission, the first part of the ejaculatory process: A role for estrogen. J. Sex. Med. 5, 2010-2016.